1
|
Giolito ML, Bigliani G, Meinero R, Taubas JV. Palmitoylation of CYSTM (CYSPD) proteins in yeast. J Biol Chem 2024; 300:105609. [PMID: 38159851 PMCID: PMC10840359 DOI: 10.1016/j.jbc.2023.105609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 12/11/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024] Open
Abstract
A superfamily of proteins called cysteine transmembrane is widely distributed across eukaryotes. These small proteins are characterized by the presence of a conserved motif at the C-terminal region, rich in cysteines, that has been annotated as a transmembrane domain. Orthologs of these proteins have been involved in resistance to pathogens and metal detoxification. The yeast members of the family are YBR016W, YDL012C, YDR034W-B, and YDR210W. Here, we begin the characterization of these proteins at the molecular level and show that Ybr016w, Ydr034w-b, and Ydr210w are palmitoylated proteins. Protein S-acylation or palmitoylation, is a posttranslational modification that consists of the addition of long-chain fatty acids to cysteine residues. We provide evidence that Ybr016w, Ydr210w, and Ydr034w-b are localized to the plasma membrane and exhibit varying degrees of polarity toward the daughter cell, which is dependent on endocytosis and recycling. We suggest the names CPP1, CPP2, and CPP3 (C terminally palmitoylated protein) for YBR016W, YDR210W, and YDR034W-B, respectively. We show that palmitoylation is responsible for the binding of these proteins to the membrane indicating that the cysteine transmembrane on these proteins is not a transmembrane domain. We propose renaming the C-terminal cysteine-rich domain as cysteine-rich palmitoylated domain. Loss of the palmitoyltransferase Erf2 leads to partial degradation of Ybr016w (Cpp1), whereas in the absence of the palmitoyltransferase Akr1, members of this family are completely degraded. For Cpp1, we show that this degradation occurs via the proteasome in an Rsp5-dependent manner, but is not exclusively due to a lack of Cpp1 palmitoylation.
Collapse
Affiliation(s)
- María Luz Giolito
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Gonzalo Bigliani
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Rocío Meinero
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina
| | - Javier Valdez Taubas
- Centro de Investigaciones en Química Biológica de Córdoba (CIQUIBIC), CONICET, Universidad Nacional de Córdoba, Córdoba, Argentina; Departamento de Química Biológica Ranwel Caputto, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Córdoba, Argentina.
| |
Collapse
|
2
|
Cho H, Liu Y, Chung S, Chandrasekar S, Weiss S, Shan SO. Dynamic stability of Sgt2 enables selective and privileged client handover in a chaperone triad. Nat Commun 2024; 15:134. [PMID: 38167697 PMCID: PMC10761869 DOI: 10.1038/s41467-023-44260-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 12/06/2023] [Indexed: 01/05/2024] Open
Abstract
Membrane protein biogenesis poses acute challenges to protein homeostasis, and how they are selectively escorted to the target membrane is not well understood. Here we address this question in the guided-entry-of-tail-anchored protein (GET) pathway, in which tail-anchored membrane proteins (TAs) are relayed through an Hsp70-Sgt2-Get3 chaperone triad for targeting to the endoplasmic reticulum. We show that the Hsp70 ATPase cycle and TA substrate drive dimeric Sgt2 from a wide-open conformation to a closed state, in which TAs are protected by both substrate binding domains of Sgt2. Get3 is privileged to receive TA from closed Sgt2, whereas off-pathway chaperones remove TAs from open Sgt2. Sgt2 closing is less favorable with suboptimal GET substrates, which are rejected during or after the Hsp70-to-Sgt2 handover. Our results demonstrate how fine-tuned conformational dynamics in Sgt2 enable hydrophobic TAs to be effectively funneled onto their dedicated targeting factor while also providing a mechanism for substrate selection.
Collapse
Affiliation(s)
- Hyunju Cho
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
- Center for Biomolecular and Cellular Structure, Institute for Basic Science, Daejeon, 34126, Republic of Korea
| | - Yumeng Liu
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
- Biochemistry and Molecular Biotechnology Department, University of Massachusetts Chan Medical School, Worcester, MA, 01655, USA
| | - SangYoon Chung
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Sowmya Chandrasekar
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA
| | - Shimon Weiss
- Department of Chemistry and Biochemistry, University of California Los Angeles, Los Angeles, CA, 90095, USA
- Department of Physics, Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan, 52900, Israel
| | - Shu-Ou Shan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA.
| |
Collapse
|
3
|
Delgado JM, Shepard LW, Lamson SW, Liu SL, Shoemaker CJ. The ER membrane protein complex restricts mitophagy by controlling BNIP3 turnover. EMBO J 2024; 43:32-60. [PMID: 38177312 PMCID: PMC10883272 DOI: 10.1038/s44318-023-00006-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 11/01/2023] [Accepted: 11/08/2023] [Indexed: 01/06/2024] Open
Abstract
Lysosomal degradation of autophagy receptors is a common proxy for selective autophagy. However, we find that two established mitophagy receptors, BNIP3 and BNIP3L/NIX, are constitutively delivered to lysosomes in an autophagy-independent manner. This alternative lysosomal delivery of BNIP3 accounts for nearly all its lysosome-mediated degradation, even upon mitophagy induction. To identify how BNIP3, a tail-anchored protein in the outer mitochondrial membrane, is delivered to lysosomes, we performed a genome-wide CRISPR screen for factors influencing BNIP3 flux. This screen revealed both known modifiers of BNIP3 stability as well as a pronounced reliance on endolysosomal components, including the ER membrane protein complex (EMC). Importantly, the endolysosomal system and the ubiquitin-proteosome system regulated BNIP3 independently. Perturbation of either mechanism is sufficient to modulate BNIP3-associated mitophagy and affect underlying cellular physiology. More broadly, these findings extend recent models for tail-anchored protein quality control and install endosomal trafficking and lysosomal degradation in the canon of pathways that tightly regulate endogenous tail-anchored protein localization.
Collapse
Affiliation(s)
- Jose M Delgado
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Logan Wallace Shepard
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Sarah W Lamson
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Samantha L Liu
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Christopher J Shoemaker
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA.
- Dartmouth Cancer Center, Lebanon, NH, USA.
| |
Collapse
|
4
|
Zvonarev A, Ledova L, Ryazanova L, Valiakhmetov A, Farofonova V, Kulakovskaya T. The YBR056W-A and Its Ortholog YDR034W-B of S. cerevisiae Belonging to CYSTM Family Participate in Manganese Stress Overcoming. Genes (Basel) 2023; 14:genes14050987. [PMID: 37239347 DOI: 10.3390/genes14050987] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/24/2023] [Accepted: 04/25/2023] [Indexed: 05/28/2023] Open
Abstract
The CYSTM (cysteine-rich transmembrane module) protein family comprises small molecular cysteine-rich tail-anchored membrane proteins found in many eukaryotes. The Saccharomyces cerevisiae strains carrying the CYSTM genes YDRO34W-B and YBR056W-A (MNC1) fused with GFP were used to test the expression of these genes under different stresses. The YBR056W-A (MNC1) and YDR034W-B genes are expressed under stress conditions caused by the toxic concentrations of heavy metal ions, such as manganese, cobalt, nickel, zinc, cuprum, and 2.4-dinitrophenol uncoupler. The expression level of YDR034W-B was higher than that of YBR056W-A under alkali and cadmium stresses. The Ydr034w-b-GFP and Ybr056w-a-GFP proteins differ in the cellular localization: Ydr034w-b-GFP was mainly observed in the plasma membrane and vacuolar membrane, while Ybr056w-a-GFP was observed in the cytoplasm, probably in intracellular membranes. The null-mutants in both genes demonstrated decreased cell concentration and lytic phenotype when cultivated in the presence of excess manganese. This allows for speculations about the involvement of Mnc1 and Ydr034w-b proteins in manganese stress overcoming.
Collapse
Affiliation(s)
- Anton Zvonarev
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Skryabin Institute of Biochemistry and Physiology of Microorganisms, 142290 Pushchino, Russia
| | - Larisa Ledova
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Skryabin Institute of Biochemistry and Physiology of Microorganisms, 142290 Pushchino, Russia
| | - Lubov Ryazanova
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Skryabin Institute of Biochemistry and Physiology of Microorganisms, 142290 Pushchino, Russia
| | - Airat Valiakhmetov
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Skryabin Institute of Biochemistry and Physiology of Microorganisms, 142290 Pushchino, Russia
| | - Vasilina Farofonova
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Institute for Biological Instrumentation of the Russian Academy of Sciences, 142290 Pushchino, Russia
| | - Tatiana Kulakovskaya
- Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Skryabin Institute of Biochemistry and Physiology of Microorganisms, 142290 Pushchino, Russia
| |
Collapse
|
5
|
Delgado JM, Wallace Shepard L, Lamson SW, Liu SL, Shoemaker CJ. The ER membrane protein complex governs lysosomal turnover of a mitochondrial tail-anchored protein, BNIP3, to restrict mitophagy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.22.533681. [PMID: 36993512 PMCID: PMC10055395 DOI: 10.1101/2023.03.22.533681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Lysosomal degradation of autophagy receptors is a common proxy for selective autophagy. However, we find that two established mitophagy receptors, BNIP3 and BNIP3L/NIX, violate this assumption. Rather, BNIP3 and NIX are constitutively delivered to lysosomes in an autophagy-independent manner. This alternative lysosomal delivery of BNIP3 accounts for nearly all of its lysosome-mediated degradation, even upon mitophagy induction. To identify how BNIP3, a tail-anchored protein in the outer mitochondrial membrane, is delivered to lysosomes, we performed a genome-wide CRISPR screen for factors influencing BNIP3 flux. By this approach, we revealed both known modifiers of BNIP3 stability as well as a pronounced reliance on endolysosomal components, including the ER membrane protein complex (EMC). Importantly, the endolysosomal system regulates BNIP3 alongside, but independent of, the ubiquitin-proteosome system (UPS). Perturbation of either mechanism is sufficient to modulate BNIP3-associated mitophagy and affect underlying cellular physiology. In short, while BNIP3 can be cleared by parallel and partially compensatory quality control pathways, non-autophagic lysosomal degradation of BNIP3 is a strong post-translational modifier of BNIP3 function. More broadly, these data reveal an unanticipated connection between mitophagy and TA protein quality control, wherein the endolysosomal system provides a critical axis for regulating cellular metabolism. Moreover, these findings extend recent models for tail-anchored protein quality control and install endosomal trafficking and lysosomal degradation in the canon of pathways that ensure tight regulation of endogenous TA protein localization.
Collapse
Affiliation(s)
- Jose M Delgado
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Logan Wallace Shepard
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Sarah W Lamson
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Samantha L Liu
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
| | - Christopher J Shoemaker
- Department of Biochemistry and Cell Biology, Geisel School of Medicine, Dartmouth College, Hanover, NH
- Dartmouth Cancer Center, Lebanon, NH, USA
| |
Collapse
|
6
|
Szabó Z, Balogh M, Domonkos Á, Csányi M, Kaló P, Kiss GB. The bs5 allele of the susceptibility gene Bs5 of pepper (Capsicum annuum L.) encoding a natural deletion variant of a CYSTM protein conditions resistance to bacterial spot disease caused by Xanthomonas species. TAG. THEORETICAL AND APPLIED GENETICS. THEORETISCHE UND ANGEWANDTE GENETIK 2023; 136:64. [PMID: 36943531 PMCID: PMC10030403 DOI: 10.1007/s00122-023-04340-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/19/2022] [Accepted: 03/02/2023] [Indexed: 05/09/2023]
Abstract
KEY MESSAGE The bs5 resistance gene against bacterial spot was identified by map-based cloning. The recessive bs5 gene of pepper (Capsicum annuum L.) conditions a non-hypersensitive resistance trait, characterized by a slightly swollen, pale green, photosynthetically active leaf tissue, following Xanthomonas euvesicatoria infection. The isolation of the bs5 gene by map-based cloning revealed that the bs5 protein was shorter by 2 amino acids as compared to the wild type Bs5 protein. The natural 2 amino acid deletion occurred in the cysteine-rich transmembrane domain of the tail-anchored (TA) protein, Ca_CYSTM1. The protein products of the wild type Bs5 and mutant bs5 genes were shown to be located in the cell membrane, indicating an unknown function in this membrane compartment. Successful infection of the Bs5 pepper lines was abolished by the 6 bp deletion in the TM encoding domain of the Ca_CYSTM1 gene in bs5 homozygotes, suggesting, that the resulting resistance might be explained by the lack of entry of the Xanthomonas specific effector molecules into the plant cells.
Collapse
Affiliation(s)
- Zoltán Szabó
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary.
| | - Márta Balogh
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary
| | - Ágota Domonkos
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary
| | - Márta Csányi
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary
| | - Péter Kaló
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary
- Institute of Plant Biology, Biological Research Center, Eötvös Lóránd Research Network, Szeged, Hungary
| | - György B Kiss
- Institute of Genetics and Biotechnology, Hungarian University of Agriculture and Life Sciences, Szent-Györgyi A. U. 4., 2100, Gödöllő, Hungary
- AMBIS Biotechnology Research and Development Ltd., Budapest, Hungary
| |
Collapse
|
7
|
Wang W, Lu J, Yang WC, Spear ED, Michaelis S, Matunis MJ. Analysis of a degron-containing reporter protein GFP-CL1 reveals a role for SUMO1 in cytosolic protein quality control. J Biol Chem 2023; 299:102851. [PMID: 36587767 PMCID: PMC9898758 DOI: 10.1016/j.jbc.2022.102851] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 12/16/2022] [Accepted: 12/19/2022] [Indexed: 12/30/2022] Open
Abstract
Misfolded proteins are recognized and degraded through protein quality control (PQC) pathways, which are essential for maintaining proteostasis and normal cellular functions. Defects in PQC can result in disease, including cancer, cardiovascular disease, and neurodegeneration. The small ubiquitin-related modifiers (SUMOs) were previously implicated in the degradation of nuclear misfolded proteins, but their functions in cytoplasmic PQC are unclear. Here, in a systematic screen of SUMO protein mutations in the budding yeast Saccharomyces cerevisiae, we identified a mutant allele (Smt3-K38A/K40A) that sensitizes cells to proteotoxic stress induced by amino acid analogs. Smt3-K38A/K40A mutant strains also exhibited a defect in the turnover of a soluble PQC model substrate containing the CL1 degron (NES-GFP-Ura3-CL1) localized in the cytoplasm, but not the nucleus. Using human U2OS SUMO1- and SUMO2-KO cell lines, we observed a similar SUMO-dependent pathway for degradation of the mammalian degron-containing PQC reporter protein, GFP-CL1, also only in the cytoplasm but not the nucleus. Moreover, we found that turnover of GFP-CL1 in the cytoplasm was uniquely dependent on SUMO1 but not the SUMO2 paralogue. Additionally, we showed that turnover of GFP-CL1 in the cytoplasm is dependent on the AAA-ATPase, Cdc48/p97. Cellular fractionation studies and analysis of a SUMO1-GFP-CL1 fusion protein revealed that SUMO1 promotes cytoplasmic misfolded protein degradation by maintaining substrate solubility. Collectively, our findings reveal a conserved and previously unrecognized role for SUMO1 in regulating cytoplasmic PQC and provide valuable insights into the roles of sumoylation in PQC-associated diseases.
Collapse
Affiliation(s)
- Wei Wang
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Jian Lu
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Wei-Chih Yang
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, USA
| | - Eric D Spear
- Department of Cell Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Susan Michaelis
- Department of Cell Biology, Johns Hopkins University, School of Medicine, Baltimore, Maryland, USA
| | - Michael J Matunis
- Department of Biochemistry and Molecular Biology, Johns Hopkins University, Bloomberg School of Public Health, Baltimore, Maryland, USA.
| |
Collapse
|
8
|
Shan SO. Role of Hsp70 in Post-Translational Protein Targeting: Tail-Anchored Membrane Proteins and Beyond. Int J Mol Sci 2023; 24:1170. [PMID: 36674686 PMCID: PMC9866221 DOI: 10.3390/ijms24021170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/02/2023] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
The Hsp70 family of molecular chaperones acts as a central 'hub' in the cell that interacts with numerous newly synthesized proteins to assist in their biogenesis. Apart from its central and well-established role in facilitating protein folding, Hsp70s also act as key decision points in the cellular chaperone network that direct client proteins to distinct biogenesis and quality control pathways. In this paper, we review accumulating data that illustrate a new branch in the Hsp70 network: the post-translational targeting of nascent membrane and organellar proteins to diverse cellular organelles. Work in multiple pathways suggests that Hsp70, via its ability to interact with components of protein targeting and translocation machineries, can initiate elaborate substrate relays in a sophisticated cascade of chaperones, cochaperones, and receptor proteins, and thus provide a mechanism to safeguard and deliver nascent membrane proteins to the correct cellular membrane. We discuss the mechanistic principles gleaned from better-studied Hsp70-dependent targeting pathways and outline the observations and outstanding questions in less well-studied systems.
Collapse
Affiliation(s)
- Shu-Ou Shan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA
| |
Collapse
|
9
|
Sagarika P, Yadav K, Sahi C. Volleying plasma membrane proteins from birth to death: Role of J-domain proteins. Front Mol Biosci 2022; 9:1072242. [PMID: 36589230 PMCID: PMC9798423 DOI: 10.3389/fmolb.2022.1072242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 12/02/2022] [Indexed: 12/23/2022] Open
Abstract
The function, stability, and turnover of plasma membrane (PM) proteins are crucial for cellular homeostasis. Compared to soluble proteins, quality control of plasma membrane proteins is extremely challenging. Failure to meet the high quality control standards is detrimental to cellular and organismal health. J-domain proteins (JDPs) are among the most diverse group of chaperones that collaborate with other chaperones and protein degradation machinery to oversee cellular protein quality control (PQC). Although fragmented, the available literature from different models, including yeast, mammals, and plants, suggests that JDPs assist PM proteins with their synthesis, folding, and trafficking to their destination as well as their degradation, either through endocytic or proteasomal degradation pathways. Moreover, some JDPs interact directly with the membrane to regulate the stability and/or functionality of proteins at the PM. The deconvoluted picture emerging is that PM proteins are relayed from one JDP to another throughout their life cycle, further underscoring the versatility of the Hsp70:JDP machinery in the cell.
Collapse
|
10
|
Modeling Adsorption, Conformation, and Orientation of the Fis1 Tail Anchor at the Mitochondrial Outer Membrane. MEMBRANES 2022; 12:membranes12080752. [PMID: 36005667 PMCID: PMC9413518 DOI: 10.3390/membranes12080752] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 12/04/2022]
Abstract
Proteins can be targeted to organellar membranes by using a tail anchor (TA), a stretch of hydrophobic amino acids found at the polypeptide carboxyl-terminus. The Fis1 protein (Fis1p), which promotes mitochondrial and peroxisomal division in the yeast Saccharomyces cerevisiae, is targeted to those organelles by its TA. Substantial evidence suggests that Fis1p insertion into the mitochondrial outer membrane can occur without the need for a translocation machinery. However, recent findings raise the possibility that Fis1p insertion into mitochondria might be promoted by a proteinaceous complex. Here, we have performed atomistic and coarse-grained molecular dynamics simulations to analyze the adsorption, conformation, and orientation of the Fis1(TA). Our results support stable insertion at the mitochondrial outer membrane in a monotopic, rather than a bitopic (transmembrane), configuration. Once inserted in the monotopic orientation, unassisted transition to the bitopic orientation is expected to be blocked by the highly charged nature of the TA carboxyl-terminus and by the Fis1p cytosolic domain. Our results are consistent with a model in which Fis1p does not require a translocation machinery for insertion at mitochondria.
Collapse
|
11
|
Sinning I, McDowell MA. Cryo-EM insights into tail-anchored membrane protein biogenesis in eukaryotes. Curr Opin Struct Biol 2022; 75:102428. [PMID: 35850079 DOI: 10.1016/j.sbi.2022.102428] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/10/2022] [Accepted: 06/16/2022] [Indexed: 11/03/2022]
Abstract
Tail-anchored (TA) proteins are a biologically significant class of membrane proteins, which require specialised cellular pathways to insert their single C-terminal transmembrane domain into the correct membrane. Cryo-electron microscopy has recently provided new insights into the organelle-specific machineries for TA protein biogenesis. Structures of targeting and insertase complexes within the canonical guided entry of TA proteins (GET) pathway indicate how substrates are faithfully chaperoned into the endoplasmic reticulum (ER) membrane in metazoans. The core of the GET insertase is conserved within structures of the ER membrane protein complex (EMC), which acts in parallel to insert a different subset of TA proteins. Furthermore, structures of the dislocases Spf1 and Msp1 show how they remove mislocalised TA proteins from the ER and outer mitochondrial membranes respectively.
Collapse
Affiliation(s)
- Irmgard Sinning
- Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
| | - Melanie A McDowell
- Max Planck Institute of Biophysics, Max-von-Laue-Strasse 3, 60438 Frankfurt Am Main, Germany.
| |
Collapse
|
12
|
Kumari D, Fisher EA, Brodsky JL. Hsp40s play distinct roles during the initial stages of apolipoprotein B biogenesis. Mol Biol Cell 2021; 33:ar15. [PMID: 34910568 PMCID: PMC9236142 DOI: 10.1091/mbc.e21-09-0436] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
Apolipoprotein B (ApoB) is the primary component of atherogenic lipoproteins, which transport serum fats and cholesterol. Therefore, elevated levels of circulating ApoB are a primary risk factor for cardiovascular disease. During ApoB biosynthesis in the liver and small intestine under nutrient-rich conditions, ApoB cotranslationally translocates into the endoplasmic reticulum (ER) and is lipidated and ultimately secreted. Under lipid-poor conditions, ApoB is targeted for ER Associated Degradation (ERAD). Although prior work identified select chaperones that regulate ApoB biogenesis, the contributions of cytoplasmic Hsp40s are undefined. To this end, we screened ApoB-expressing yeast and determined that a class A ER-associated Hsp40, Ydj1, associates with and facilitates the ERAD of ApoB. Consistent with these results, a homologous Hsp40, DNAJA1, functioned similarly in rat hepatoma cells. DNAJA1 deficient cells also secreted hyperlipidated lipoproteins, in accordance with attenuated ERAD. In contrast to the role of DNAJA1 during ERAD, DNAJB1-a class B Hsp40-helped stabilize ApoB. Depletion of DNAJA1 and DNAJB1 also led to opposing effects on ApoB ubiquitination. These data represent the first example in which different Hsp40s exhibit disparate effects during regulated protein biogenesis in the ER, and highlight distinct roles that chaperones can play on a single ERAD substrate.
Collapse
Affiliation(s)
- Deepa Kumari
- Department of Biological Sciences, A320 Langley Hall, Fifth & Ruskin Ave, University of Pittsburgh, Pittsburgh, PA 15260 USA
| | - Edward A Fisher
- Department of Medicine, Leon H. Charney Division of Cardiology, Cardiovascular Research Center, New York University Grossman School of Medicine, New York, United States
| | - Jeffrey L Brodsky
- Department of Biological Sciences, A320 Langley Hall, Fifth & Ruskin Ave, University of Pittsburgh, Pittsburgh, PA 15260 USA
| |
Collapse
|
13
|
Mehlhorn DG, Asseck LY, Grefen C. Looking for a safe haven: tail-anchored proteins and their membrane insertion pathways. PLANT PHYSIOLOGY 2021; 187:1916-1928. [PMID: 35235667 PMCID: PMC8644595 DOI: 10.1093/plphys/kiab298] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Accepted: 06/05/2021] [Indexed: 06/14/2023]
Abstract
Insertion of membrane proteins into the lipid bilayer is a crucial step during their biosynthesis. Eukaryotic cells face many challenges in directing these proteins to their predestined target membrane. The hydrophobic signal peptide or transmembrane domain (TMD) of the nascent protein must be shielded from the aqueous cytosol and its target membrane identified followed by transport and insertion. Components that evolved to deal with each of these challenging steps range from chaperones to receptors, insertases, and sophisticated translocation complexes. One prominent translocation pathway for most proteins is the signal recognition particle (SRP)-dependent pathway which mediates co-translational translocation of proteins across or into the endoplasmic reticulum (ER) membrane. This textbook example of protein insertion is stretched to its limits when faced with secretory or membrane proteins that lack an amino-terminal signal sequence or TMD. Particularly, a large group of so-called tail-anchored (TA) proteins that harbor a single carboxy-terminal TMD require an alternative, post-translational insertion route into the ER membrane. In this review, we summarize the current research in TA protein insertion with a special focus on plants, address challenges, and highlight future research avenues.
Collapse
Affiliation(s)
- Dietmar G Mehlhorn
- Faculty of Biology and Biotechnology, Molecular and Cellular Botany, University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Lisa Y Asseck
- Faculty of Biology and Biotechnology, Molecular and Cellular Botany, University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| | - Christopher Grefen
- Faculty of Biology and Biotechnology, Molecular and Cellular Botany, University of Bochum, Universitätsstraße 150, 44780 Bochum, Germany
| |
Collapse
|
14
|
Kumar T, Maitra S, Rahman A, Bhattacharjee S. A conserved guided entry of tail-anchored pathway is involved in the trafficking of a subset of membrane proteins in Plasmodium falciparum. PLoS Pathog 2021; 17:e1009595. [PMID: 34780541 PMCID: PMC8629386 DOI: 10.1371/journal.ppat.1009595] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 11/29/2021] [Accepted: 10/19/2021] [Indexed: 01/22/2023] Open
Abstract
Tail-anchored (TA) proteins are defined by the absence of N-terminus signal sequence and the presence of a single transmembrane domain (TMD) proximal to their C-terminus. They play fundamental roles in cellular processes including vesicular trafficking, protein translocation and quality control. Some of the TA proteins are post-translationally integrated by the Guided Entry of TA (GET) pathway to the cellular membranes; with their N-terminus oriented towards the cytosol and C-terminus facing the organellar lumen. The TA repertoire and the GET machinery have been extensively characterized in the yeast and mammalian systems, however, they remain elusive in the human malaria parasite Plasmodium falciparum. In this study, we bioinformatically predicted a total of 63 TA proteins in the P. falciparum proteome and revealed the association of a subset with the P. falciparum homolog of Get3 (PfGet3). In addition, our proximity labelling studies either definitively identified or shortlisted the other eligible GET constituents, and our in vitro association studies validated associations between PfGet3 and the corresponding homologs of Get4 and Get2 in P. falciparum. Collectively, this study reveals the presence of proteins with hallmark TA signatures and the involvement of evolutionary conserved GET trafficking pathway for their targeted delivery within the parasite. Tail-anchored (TA) membrane proteins are known to play essential cellular functions in the eukaryotes. These proteins are trafficked to their respective destinations by post-translational translocation pathways that are evolutionarily conserved from yeast to human. However, they remain unidentified in the malaria parasite Plasmodium falciparum. We have used bioinformatic prediction algorithms in conjunction with functional validation studies to identify the candidate TA repertoire and some of the homologs of the trafficking machinery in P. falciparum. Initially, we predicted the presence of 63 putative TA proteins localized to distinct compartments within this parasite, including a few confirmed TA homologs in other eukaryotic systems. We then identified and characterized PfGet3 as a central component in the Guided-Entry of TA (GET) translocation machinery, and our bacterial co-expression and pulldown assays with two selected recombinant TA proteins, PfBOS1 and PfUSE1, showed co-association with PfGet3. We also identified PfGet2 and PfGet4 as the other two components of the GET machinery in P. falciparum using proximity biotinylation followed by mass spectrometry. Interestingly, we also found six TA proteins in the parasite enriched in this fraction. We further validated the direct interactions between a few TA candidates, PfGet4 and PfGet2 with PfGet3 using recombinant-based pulldown studies. In conclusion, this study classified a subset of membrane proteins with the TA nomenclature and implicated a previously unidentified GET pathway for their translocation in this apicomplexan parasite.
Collapse
Affiliation(s)
- Tarkeshwar Kumar
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Satarupa Maitra
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Abdur Rahman
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
| | - Souvik Bhattacharjee
- Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India
- * E-mail:
| |
Collapse
|
15
|
Fry MY, Saladi SM, Cunha A, Clemons WM. Sequence-based features that are determinant for tail-anchored membrane protein sorting in eukaryotes. Traffic 2021; 22:306-318. [PMID: 34288289 PMCID: PMC8380732 DOI: 10.1111/tra.12809] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/15/2021] [Accepted: 07/18/2021] [Indexed: 11/29/2022]
Abstract
The correct targeting and insertion of tail-anchored (TA) integral membrane proteins is critical for cellular homeostasis. TA proteins are defined by a hydrophobic transmembrane domain (TMD) at their C-terminus and are targeted to either the ER or mitochondria. Derived from experimental measurements of a few TA proteins, there has been little examination of the TMD features that determine localization. As a result, the localization of many TA proteins are misclassified by the simple heuristic of overall hydrophobicity. Because ER-directed TMDs favor arrangement of hydrophobic residues to one side, we sought to explore the role of geometric hydrophobic properties. By curating TA proteins with experimentally determined localizations and assessing hypotheses for recognition, we bioinformatically and experimentally verify that a hydrophobic face is the most accurate singular metric for separating ER and mitochondria-destined yeast TA proteins. A metric focusing on an 11 residue segment of the TMD performs well when classifying human TA proteins. The most inclusive predictor uses both hydrophobicity and C-terminal charge in tandem. This work provides context for previous observations and opens the door for more detailed mechanistic experiments to determine the molecular factors driving this recognition.
Collapse
Affiliation(s)
- Michelle Y. Fry
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Shyam M. Saladi
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| | - Alexandre Cunha
- Division of Biology and Biological Engineering, Center for Advanced Methods in Biological Image Analysis, Beckman Institute, Pasadena, California, USA
| | - William M. Clemons
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California, USA
| |
Collapse
|
16
|
Coukos R, Yao D, Sanchez MI, Strand ET, Olive ME, Udeshi ND, Weissman JS, Carr SA, Bassik MC, Ting AY. An engineered transcriptional reporter of protein localization identifies regulators of mitochondrial and ER membrane protein trafficking in high-throughput CRISPRi screens. eLife 2021; 10:69142. [PMID: 34414886 PMCID: PMC8423448 DOI: 10.7554/elife.69142] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/18/2021] [Indexed: 12/12/2022] Open
Abstract
The trafficking of specific protein cohorts to correct subcellular locations at correct times is essential for every signaling and regulatory process in biology. Gene perturbation screens could provide a powerful approach to probe the molecular mechanisms of protein trafficking, but only if protein localization or mislocalization can be tied to a simple and robust phenotype for cell selection, such as cell proliferation or fluorescence-activated cell sorting (FACS). To empower the study of protein trafficking processes with gene perturbation, we developed a genetically encoded molecular tool named HiLITR (High-throughput Localization Indicator with Transcriptional Readout). HiLITR converts protein colocalization into proteolytic release of a membrane-anchored transcription factor, which drives the expression of a chosen reporter gene. Using HiLITR in combination with FACS-based CRISPRi screening in human cell lines, we identified genes that influence the trafficking of mitochondrial and ER tail-anchored proteins. We show that loss of the SUMO E1 component SAE1 results in mislocalization and destabilization of many mitochondrial tail-anchored proteins. We also demonstrate a distinct regulatory role for EMC10 in the ER membrane complex, opposing the transmembrane-domain insertion activity of the complex. Through transcriptional integration of complex cellular functions, HiLITR expands the scope of biological processes that can be studied by genetic perturbation screening technologies.
Collapse
Affiliation(s)
- Robert Coukos
- Department of Genetics, Stanford University, Stanford, United States
| | - David Yao
- Department of Genetics, Stanford University, Stanford, United States
| | - Mateo I Sanchez
- Department of Genetics, Stanford University, Stanford, United States.,Chan Zuckerberg Biohub, Stanford, United States
| | - Eric T Strand
- Department of Genetics, Stanford University, Stanford, United States
| | - Meagan E Olive
- Broad Institute of MIT and Harvard, Cambridge, United States
| | | | - Jonathan S Weissman
- Whitehead Institute, Cambridge, United States.,Department of Biology, Massachusetts Institute of Technology, Cambridge, United States.,Department of Cellular and Molecular Pharmacology, University of California, San Francisco, San Francisco, United States.,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, United States
| | - Steven A Carr
- Broad Institute of MIT and Harvard, Cambridge, United States
| | - Michael C Bassik
- Department of Genetics, Stanford University, Stanford, United States
| | - Alice Y Ting
- Department of Genetics, Stanford University, Stanford, United States.,Chan Zuckerberg Biohub, Stanford, United States.,Department of Biology, Stanford University, Stanford, United States
| |
Collapse
|
17
|
Farkas Á, Bohnsack KE. Capture and delivery of tail-anchored proteins to the endoplasmic reticulum. J Cell Biol 2021; 220:212470. [PMID: 34264263 PMCID: PMC8287540 DOI: 10.1083/jcb.202105004] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 06/20/2021] [Accepted: 06/22/2021] [Indexed: 11/22/2022] Open
Abstract
Tail-anchored (TA) proteins fulfill diverse cellular functions within different organellar membranes. Their characteristic C-terminal transmembrane segment renders TA proteins inherently prone to aggregation and necessitates their posttranslational targeting. The guided entry of TA proteins (GET in yeast)/transmembrane recognition complex (TRC in humans) pathway represents a major route for TA proteins to the endoplasmic reticulum (ER). Here, we review important new insights into the capture of nascent TA proteins at the ribosome by the GET pathway pretargeting complex and the mechanism of their delivery into the ER membrane by the GET receptor insertase. Interestingly, several alternative routes by which TA proteins can be targeted to the ER have emerged, raising intriguing questions about how selectivity is achieved during TA protein capture. Furthermore, mistargeting of TA proteins is a fundamental cellular problem, and we discuss the recently discovered quality control machineries in the ER and outer mitochondrial membrane for displacing mislocalized TA proteins.
Collapse
Affiliation(s)
- Ákos Farkas
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| |
Collapse
|
18
|
James C, Kehlenbach RH. The Interactome of the VAP Family of Proteins: An Overview. Cells 2021; 10:cells10071780. [PMID: 34359948 PMCID: PMC8306308 DOI: 10.3390/cells10071780] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/28/2021] [Accepted: 07/08/2021] [Indexed: 12/11/2022] Open
Abstract
Membrane contact sites (MCS) are sites of close apposition of two organelles that help in lipid transport and synthesis, calcium homeostasis and several other biological processes. The VAMP-associated proteins (VAPs) VAPA, VAPB, MOSPD2 and the recently described MOSPD1 and MOSPD3 are tether proteins of MCSs that are mainly found at the endoplasmic reticulum (ER). VAPs interact with various proteins with a motif called FFAT (two phenylalanines in an acidic tract), recruiting the associated organelle to the ER. In addition to the conventional FFAT motif, the recently described FFNT (two phenylalanines in a neutral tract) and phospho-FFAT motifs contribute to the interaction with VAPs. In this review, we summarize and compare the recent interactome studies described for VAPs, including in silico and proximity labeling methods. Collectively, the interaction repertoire of VAPs is very diverse and highlights the complexity of interactions mediated by the different FFAT motifs to the VAPs.
Collapse
|
19
|
Innokentev A, Furukawa K, Fukuda T, Saigusa T, Inoue K, Yamashita SI, Kanki T. Association and dissociation between the mitochondrial Far complex and Atg32 regulate mitophagy. eLife 2020; 9:63694. [PMID: 33317697 PMCID: PMC7738187 DOI: 10.7554/elife.63694] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 11/27/2020] [Indexed: 12/17/2022] Open
Abstract
Mitophagy plays an important role in mitochondrial homeostasis. In yeast, the phosphorylation of the mitophagy receptor Atg32 by casein kinase 2 is essential for mitophagy. This phosphorylation is counteracted by the yeast equivalent of the STRIPAK complex consisting of the PP2A-like protein phosphatase Ppg1 and Far3-7-8-9-10-11 (Far complex), but the underlying mechanism remains elusive. Here we show that two subpopulations of the Far complex reside in the mitochondria and endoplasmic reticulum, respectively, and play distinct roles; the former inhibits mitophagy via Atg32 dephosphorylation, and the latter regulates TORC2 signaling. Ppg1 and Far11 form a subcomplex, and Ppg1 activity is required for the assembling integrity of Ppg1-Far11-Far8. The Far complex preferentially interacts with phosphorylated Atg32, and this interaction is weakened by mitophagy induction. Furthermore, the artificial tethering of Far8 to Atg32 prevents mitophagy. Taken together, the Ppg1-mediated Far complex formation and its dissociation from Atg32 are crucial for mitophagy regulation.
Collapse
Affiliation(s)
- Aleksei Innokentev
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Kentaro Furukawa
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomoyuki Fukuda
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tetsu Saigusa
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Keiichi Inoue
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Shun-Ichi Yamashita
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| | - Tomotake Kanki
- Department of Cellular Physiology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
| |
Collapse
|
20
|
Jiang H. Quality control pathways of tail-anchored proteins. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2020; 1868:118922. [PMID: 33285177 DOI: 10.1016/j.bbamcr.2020.118922] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/14/2020] [Accepted: 12/01/2020] [Indexed: 12/20/2022]
Abstract
Tail-anchored (TA) proteins have an N-terminal domain in the cytosol and a C-terminal transmembrane domain anchored to a variety of organelle membranes. TA proteins are recognized by targeting factors at the transmembrane domain and C-terminal sequence and are guided to distinct membranes. The promiscuity of targeting sequences and the dysfunction of targeting pathways cause mistargeting of TA proteins. TA proteins are under surveillance by quality control pathways. For resident TA proteins at mitochondrial and ER membranes, intrinsic instability or stimuli induced degrons of the cytosolic and transmembrane domains are sensed by quality control factors to initiate degradation of TA proteins. These pathways are summarized as TA protein degradation-Cytosol (TAD-C) and TAD-Membrane (TAD-M) pathways. For mistargeted and a subset of solitary TA proteins at mitochondrial and peroxisomal membranes, a unique pathway has been revealed in recent years. Msp1/ATAD1 is an AAA-ATPase dually-localized to mitochondrial and peroxisomal membranes. It directly recognizes mistargeted and solitary TA proteins and dislocates them out of membrane. Dislocated substrates are subsequently ubiquitinated by the ER-resident Doa10 ubiquitin E3 ligase complex for degradation. We summarize and discuss the substrate recognition, dislocation and degradation mechanisms of the Msp1 pathway.
Collapse
Affiliation(s)
- Hui Jiang
- National Institute of Biological Sciences, Beijing 102206, China; Beijing Key Laboratory of Cell Biology for Animal Aging, Beijing 102206, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100871, China.
| |
Collapse
|
21
|
Wang L, Walter P. Msp1/ATAD1 in Protein Quality Control and Regulation of Synaptic Activities. Annu Rev Cell Dev Biol 2020; 36:141-164. [DOI: 10.1146/annurev-cellbio-031220-015840] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Mitochondrial function depends on the efficient import of proteins synthesized in the cytosol. When cells experience stress, the efficiency and faithfulness of the mitochondrial protein import machinery are compromised, leading to homeostatic imbalances and damage to the organelle. Yeast Msp1 (mitochondrial sorting of proteins 1) and mammalian ATAD1 (ATPase family AAA domain–containing 1) are orthologous AAA proteins that, fueled by ATP hydrolysis, recognize and extract mislocalized membrane proteins from the outer mitochondrial membrane. Msp1 also extracts proteins that have become stuck in the import channel. The extracted proteins are targeted for proteasome-dependent degradation or, in the case of mistargeted tail-anchored proteins, are given another chance to be routed correctly. In addition, ATAD1 is implicated in the regulation of synaptic plasticity, mediating the release of neurotransmitter receptors from postsynaptic scaffolds to allow their trafficking. Here we discuss how structural and functional specialization imparts the unique properties that allow Msp1/ATAD1 ATPases to fulfill these diverse functions and also highlight outstanding questions in the field.
Collapse
Affiliation(s)
- Lan Wang
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143, USA;,
| | - Peter Walter
- Department of Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143, USA;,
- Howard Hughes Medical Institute, University of California at San Francisco, San Francisco, California 94122, USA
| |
Collapse
|
22
|
Kubalová D, Káňovičová P, Veselá P, Awadová T, Džugasová V, Daum G, Malínský J, Balážová M. The lipid droplet protein Pgc1 controls the subcellular distribution of phosphatidylglycerol. FEMS Yeast Res 2020; 19:5524364. [PMID: 31247640 DOI: 10.1093/femsyr/foz045] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2019] [Accepted: 06/26/2019] [Indexed: 12/12/2022] Open
Abstract
The biosynthesis of yeast phosphatidylglycerol (PG) takes place in the inner mitochondrial membrane. Outside mitochondria, the abundance of PG is low. Here, we present evidence that the subcellular distribution of PG is maintained by the locally controlled enzymatic activity of the PG-specific phospholipase, Pgc1. A fluorescently labeled Pgc1 protein accumulates on the surface of lipid droplets (LD). We show, however, that LD are not only dispensable for Pgc1-mediated PG degradation, but do not even host any phospholipase activity of Pgc1. Our in vitro assays document the capability of LD-accumulated Pgc1 to degrade PG upon entry to the membranes of the endoplasmic reticulum, mitochondria and even of artificial phospholipid vesicles. Fluorescence recovery after photobleaching analysis confirms the continuous exchange of GFP-Pgc1 within the individual LD in situ, suggesting that a steady-state equilibrium exists between LD and membranes to regulate the immediate phospholipase activity of Pgc1. In this model, LD serve as a storage place and shelter Pgc1, preventing its untimely degradation, while both phospholipase activity and degradation of the enzyme occur in the membranes.
Collapse
Affiliation(s)
- Dominika Kubalová
- Department of Membrane Biochemistry, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, 84005 Bratislava, Slovakia
| | - Paulína Káňovičová
- Department of Membrane Biochemistry, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, 84005 Bratislava, Slovakia
| | - Petra Veselá
- Department of Microscopy, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic,14220 Prague, Czech Republic
| | - Thuraya Awadová
- Department of Microscopy, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic,14220 Prague, Czech Republic
| | - Vladimíra Džugasová
- Department of Genetics, Faculty of Natural Sciences, Comenius University, 84215 Bratislava, Slovakia
| | - Günther Daum
- Institute of Biochemistry, Graz University of Technology, 8010 Graz, Austria
| | - Jan Malínský
- Department of Microscopy, Institute of Experimental Medicine, Academy of Sciences of the Czech Republic,14220 Prague, Czech Republic
| | - Mária Balážová
- Department of Membrane Biochemistry, Institute of Animal Biochemistry and Genetics, Centre of Biosciences, Slovak Academy of Sciences, 84005 Bratislava, Slovakia
| |
Collapse
|
23
|
Neveu E, Khalifeh D, Salamin N, Fasshauer D. Prototypic SNARE Proteins Are Encoded in the Genomes of Heimdallarchaeota, Potentially Bridging the Gap between the Prokaryotes and Eukaryotes. Curr Biol 2020; 30:2468-2480.e5. [PMID: 32442459 DOI: 10.1016/j.cub.2020.04.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Revised: 04/05/2020] [Accepted: 04/23/2020] [Indexed: 12/15/2022]
Abstract
A defining feature of eukaryotic cells is the presence of numerous membrane-bound organelles that subdivide the intracellular space into distinct compartments. How the eukaryotic cell acquired its internal complexity is still poorly understood. Material exchange among most organelles occurs via vesicles that bud off from a source and specifically fuse with a target compartment. Central players in the vesicle fusion process are the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins. These small tail-anchored (TA) membrane proteins zipper into elongated four-helix bundles that pull membranes together. SNARE proteins are highly conserved among eukaryotes but are thought to be absent in prokaryotes. Here, we identified SNARE-like factors in the genomes of uncultured organisms of Asgard archaea of the Heimdallarchaeota clade, which are thought to be the closest living relatives of eukaryotes. Biochemical experiments show that the archaeal SNARE-like proteins can interact with eukaryotic SNARE proteins. We did not detect SNAREs in α-proteobacteria, the closest relatives of mitochondria, but identified several genes encoding for SNARE proteins in γ-proteobacteria of the order Legionellales, pathogens that live inside eukaryotic cells. Very probably, their SNAREs stem from lateral gene transfer from eukaryotes. Together, this suggests that the diverse set of eukaryotic SNAREs evolved from an archaeal precursor. However, whether Heimdallarchaeota actually have a simplified endomembrane system will only be seen when we succeed studying these organisms under the microscope.
Collapse
Affiliation(s)
- Emilie Neveu
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, Génopode, 1015 Lausanne, Switzerland
| | - Dany Khalifeh
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, Génopode, 1015 Lausanne, Switzerland
| | - Nicolas Salamin
- Department of Computational Biology, University of Lausanne, Génopode, 1015 Lausanne, Switzerland
| | - Dirk Fasshauer
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland; Department of Computational Biology, University of Lausanne, Génopode, 1015 Lausanne, Switzerland.
| |
Collapse
|
24
|
Extranuclear Structural Components that Mediate Dynamic Chromosome Movements in Yeast Meiosis. Curr Biol 2020; 30:1207-1216.e4. [PMID: 32059771 DOI: 10.1016/j.cub.2020.01.054] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 11/20/2019] [Accepted: 01/16/2020] [Indexed: 02/02/2023]
Abstract
Telomere-led rapid chromosome movements or rapid prophase movements direct fundamental meiotic processes required for successful haploidization of the genome. Critical components of the machinery that generates rapid prophase movements are unknown, and the mechanism underlying rapid prophase movements remains poorly understood. We identified S. cerevisiae Mps2 as the outer nuclear membrane protein that connects the LINC complex with the cytoskeleton. We also demonstrate that the motor Myo2 works together with Mps2 to couple the telomeres to the actin cytoskeleton. Further, we show that Csm4 interacts with Mps2 and is required for perinuclear localization of Myo2, implicating Csm4 as a regulator of the Mps2-Myo2 interaction. We propose a model in which the newly identified functions of Mps2 and Myo2 cooperate with Csm4 to drive chromosome movements in meiotic prophase by coupling telomeres to the actin cytoskeleton.
Collapse
|
25
|
Abstract
Due to their topology tail-anchored (TA) proteins must target to the membrane independently of the co-translational route defined by the signal sequence recognition particle (SRP), its receptor and the translocon Sec61. More than a decade of work has extensively characterized a highly conserved pathway, the yeast GET or mammalian TRC40 pathway, which is capable of countering the biogenetic challenge posed by the C-terminal TA anchor. In this review we briefly summarize current models of this targeting route and focus on emerging aspects such as the intricate interplay with the proteostatic network of cells and with other targeting pathways. Importantly, we consider the lessons provided by the in vivo analysis of the pathway in different model organisms and by the consideration of its full client spectrum in more recent studies. This analysis of the state of the field highlights directions in which the current models may be experimentally probed and conceptually extended.
Collapse
Affiliation(s)
- Nica Borgese
- Institute of Neuroscience and BIOMETRA Department, Consiglio Nazionale delle Ricerche and Università degli Studi di Milano, via Vanvitelli 32, 20129, Milan, Italy.
| | - Javier Coy-Vergara
- Department of Molecular Biology, University of Göttingen Medical Centre, Humboldtallee 23, 37073, Göttingen, Germany
| | - Sara Francesca Colombo
- Institute of Neuroscience and BIOMETRA Department, Consiglio Nazionale delle Ricerche and Università degli Studi di Milano, via Vanvitelli 32, 20129, Milan, Italy
| | - Blanche Schwappach
- Department of Molecular Biology, University of Göttingen Medical Centre, Humboldtallee 23, 37073, Göttingen, Germany.
| |
Collapse
|
26
|
Brito GC, Schormann W, Gidda SK, Mullen RT, Andrews DW. Genome-wide analysis of Homo sapiens, Arabidopsis thaliana, and Saccharomyces cerevisiae reveals novel attributes of tail-anchored membrane proteins. BMC Genomics 2019; 20:835. [PMID: 31711414 PMCID: PMC6849228 DOI: 10.1186/s12864-019-6232-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 10/28/2019] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Tail-anchored membrane proteins (TAMPs) differ from other integral membrane proteins, because they contain a single transmembrane domain at the extreme carboxyl-terminus and are therefore obliged to target to membranes post-translationally. Although 3-5% of all transmembrane proteins are predicted to be TAMPs only a small number are well characterized. RESULTS To identify novel putative TAMPs across different species, we used TAMPfinder software to identify 859, 657 and 119 putative TAMPs in human (Homo sapiens), plant (Arabidopsis thaliana), and yeast (Saccharomyces cerevisiae), respectively. Bioinformatics analyses of these putative TAMP sequences suggest that the list is highly enriched for authentic TAMPs. To experimentally validate the software predictions several human and plant proteins identified by TAMPfinder that were previously uncharacterized were expressed in cells and visualized at subcellular membranes by fluorescence microscopy and further analyzed by carbonate extraction or by bimolecular fluorescence complementation. With the exception of the pro-apoptotic protein harakiri, which is, peripherally bound to the membrane this subset of novel proteins behave like genuine TAMPs. Comprehensive bioinformatics analysis of the generated TAMP datasets revealed previously unappreciated common and species-specific features such as the unusual size distribution of and the propensity of TAMP proteins to be part of larger complexes. Additionally, novel features of the amino acid sequences that anchor TAMPs to membranes were also revealed. CONCLUSIONS The findings in this study more than double the number of predicted annotated TAMPs and provide new insights into the common and species-specific features of TAMPs. Furthermore, the list of TAMPs and annotations provide a resource for further investigation.
Collapse
Affiliation(s)
- Glauber Costa Brito
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Wiebke Schormann
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada
| | - Satinder K Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, N1G 2W1, Canada
| | - David W Andrews
- Biological Sciences, Sunnybrook Research Institute, Toronto, ON, M4N 3M5, Canada. .,Departments of Biochemistry and Medical Biophysics, University of Toronto, Toronto, ON, Canada.
| |
Collapse
|
27
|
Zauner S, Heimerl T, Moog D, Maier UG. The Known, the New, and a Possible Surprise: A Re-Evaluation of the Nucleomorph-Encoded Proteome of Cryptophytes. Genome Biol Evol 2019; 11:1618-1629. [PMID: 31124562 PMCID: PMC6559170 DOI: 10.1093/gbe/evz109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2019] [Indexed: 01/01/2023] Open
Abstract
Nucleomorphs are small nuclei that evolved from the nucleus of former eukaryotic endosymbionts of cryptophytes and chlorarachniophytes. These enigmatic organelles reside in their complex plastids and harbor the smallest and most compacted eukaryotic genomes investigated so far. Although the coding capacity of the nucleomorph genomes is small, a significant percentage of the encoded proteins (predicted nucleomorph-encoded proteins, pNMPs) is still not functionally annotated. We have analyzed pNMPs with unknown functions via Phyre2, a bioinformatic tool for prediction and modeling of protein structure, resulting in a functional annotation of 215 pNMPs out of 826 uncharacterized open reading frames of cryptophytes. The newly annotated proteins are predicted to participate in nucleomorph-specific functions such as chromosome organization and expression, as well as in modification and degradation of nucleomorph-encoded proteins. Additionally, we have functionally assigned nucleomorph-encoded, putatively plastid-targeted proteins among the reinvestigated pNMPs. Hints for a putative function in the periplastid compartment, the cytoplasm surrounding the nucleomorphs, emerge from the identification of pNMPs that might be homologs of endomembrane system-related proteins. These proteins are discussed in respect to their putative functions.
Collapse
Affiliation(s)
- Stefan Zauner
- Department for Cell Biology, Philipps-Universität Marburg, Germany
| | - Thomas Heimerl
- SYNMIKRO Research Center, Philipps-Universität Marburg, Germany
| | - Daniel Moog
- Department for Cell Biology, Philipps-Universität Marburg, Germany.,SYNMIKRO Research Center, Philipps-Universität Marburg, Germany
| | - Uwe G Maier
- Department for Cell Biology, Philipps-Universität Marburg, Germany.,SYNMIKRO Research Center, Philipps-Universität Marburg, Germany
| |
Collapse
|
28
|
Slee JA, Levine TP. Systematic prediction of FFAT motifs across eukaryote proteomes identifies nucleolar and eisosome proteins with the predicted capacity to form bridges to the endoplasmic reticulum. ACTA ACUST UNITED AC 2019; 2:1-21. [PMID: 31777772 DOI: 10.1177/2515256419883136] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The endoplasmic reticulum (ER), the most pervasive organelle, exchanges information and material with many other organelles, but the extent of its inter-organelle connections and the proteins that form bridges are not well known. The integral ER membrane protein VAMP-associated protein (VAP) is found in multiple bridges, interacting with many proteins that contain a short linear motif consisting of "two phenylalanines in an acidic tract" (FFAT). The VAP-FFAT interaction is the most common mechanism by which cytoplasmic proteins, particularly inter-organelle bridges, target the ER. Therefore, predicting new FFAT motifs may both find new individual peripheral ER proteins and identify new routes of communication involving the ER. Here we searched for FFAT motifs across whole proteomes. The excess of eukaryotic proteins with FFAT motifs over background was ≥0.8%, suggesting this is the minimum number of peripheral ER proteins. In yeast, where VAP was previously known to bind 4 proteins with FFAT motifs, a detailed analysis of a subset of proteins predicted 20 FFAT motifs. Extrapolating these findings to the whole proteome estimated the number of FFAT motifs in yeast at approximately 50-55 (0.9% of proteome). Among these previously unstudied FFAT motifs, most have known functions outside the ER, so could be involved in inter-organelle communication. Many of these can target well-characterised membrane contact sites, however some are in nucleoli and eisosomes, organelles previously unknown to have molecular bridges to the ER. We speculate that the nucleolar and eisosomal proteins with predicted motifs may function while bridging to the ER, indicating novel ER-nucleolus and ER-eisosome routes of inter-organelle communication.
Collapse
Affiliation(s)
| | - Timothy P Levine
- UCL Institute of Ophthalmology, 11-43 Bath Street, London EC1V 9EL, UK
| |
Collapse
|
29
|
A Humanized Yeast Phenomic Model of Deoxycytidine Kinase to Predict Genetic Buffering of Nucleoside Analog Cytotoxicity. Genes (Basel) 2019; 10:genes10100770. [PMID: 31575041 PMCID: PMC6826991 DOI: 10.3390/genes10100770] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 09/17/2019] [Accepted: 09/23/2019] [Indexed: 12/22/2022] Open
Abstract
Knowledge about synthetic lethality can be applied to enhance the efficacy of anticancer therapies in individual patients harboring genetic alterations in their cancer that specifically render it vulnerable. We investigated the potential for high-resolution phenomic analysis in yeast to predict such genetic vulnerabilities by systematic, comprehensive, and quantitative assessment of drug–gene interaction for gemcitabine and cytarabine, substrates of deoxycytidine kinase that have similar molecular structures yet distinct antitumor efficacy. Human deoxycytidine kinase (dCK) was conditionally expressed in the Saccharomyces cerevisiae genomic library of knockout and knockdown (YKO/KD) strains, to globally and quantitatively characterize differential drug–gene interaction for gemcitabine and cytarabine. Pathway enrichment analysis revealed that autophagy, histone modification, chromatin remodeling, and apoptosis-related processes influence gemcitabine specifically, while drug–gene interaction specific to cytarabine was less enriched in gene ontology. Processes having influence over both drugs were DNA repair and integrity checkpoints and vesicle transport and fusion. Non-gene ontology (GO)-enriched genes were also informative. Yeast phenomic and cancer cell line pharmacogenomics data were integrated to identify yeast–human homologs with correlated differential gene expression and drug efficacy, thus providing a unique resource to predict whether differential gene expression observed in cancer genetic profiles are causal in tumor-specific responses to cytotoxic agents.
Collapse
|
30
|
Weill U, Cohen N, Fadel A, Ben-Dor S, Schuldiner M. Protein Topology Prediction Algorithms Systematically Investigated in the Yeast Saccharomyces cerevisiae. Bioessays 2019; 41:e1800252. [PMID: 31297843 DOI: 10.1002/bies.201800252] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Revised: 05/05/2019] [Indexed: 11/09/2022]
Abstract
Membrane proteins perform a variety of functions, all crucially dependent on their orientation in the membrane. However, neither the exact number of transmembrane domains (TMDs) nor the topology of most proteins have been experimentally determined. Due to this, most scientists rely primarily on prediction algorithms to determine topology and TMD assignments. Since these can give contradictory results, single-algorithm-based predictions are unreliable. To map the extent of potential misanalysis, the predictions of nine algorithms on the yeast proteome are compared and it is found that they have little agreement when predicting TMD number and termini orientation. To view all predictions in parallel, a webpage called TopologYeast: http://www.weizmann.ac.il/molgen/TopologYeast was created. Each algorithm is compared with experimental data and a poor agreement is found. The analysis suggests that more systematic data on protein topology are required to increase the training sets for prediction algorithms and to have accurate knowledge of membrane protein topology.
Collapse
Affiliation(s)
- Uri Weill
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Nir Cohen
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Amir Fadel
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Shifra Ben-Dor
- Department of Life Sciences Core Facilities, Weizmann Institute of Science, Rehovot, 7610001, Israel
| | - Maya Schuldiner
- Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, 7610001, Israel
| |
Collapse
|
31
|
Lin TW, Chen CC, Wu SM, Chang YC, Li YC, Su YW, Hsiao CD, Chang HY. Structural analysis of chloroplast tail-anchored membrane protein recognition by ArsA1. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2019; 99:128-143. [PMID: 30891827 DOI: 10.1111/tpj.14316] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2018] [Revised: 02/26/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
In mammals and yeast, tail-anchored (TA) membrane proteins destined for the post-translational pathway are safely delivered to the endoplasmic reticulum (ER) membrane by a well-known targeting factor, TRC40/Get3. In contrast, the underlying mechanism for translocation of TA proteins in plants remains obscure. How this unique eukaryotic membrane-trafficking system correctly distinguishes different subsets of TA proteins destined for various organelles, including mitochondria, chloroplasts and the ER, is a key question of long standing. Here, we present crystal structures of algal ArsA1 (the Get3 homolog) in a distinct nucleotide-free open state and bound to adenylyl-imidodiphosphate. This approximately 80-kDa protein possesses a monomeric architecture, with two ATPase domains in a single polypeptide chain. It is capable of binding chloroplast (TOC34 and TOC159) and mitochondrial (TOM7) TA proteins based on features of its transmembrane domain as well as the regions immediately before and after the transmembrane domain. Several helices located above the TA-binding groove comprise the interlocking hook-like motif implicated by mutational analyses in TA substrate recognition. Our data provide insights into the molecular basis of the highly specific selectivity of interactions of algal ArsA1 with the correct sets of TA substrates before membrane targeting in plant cells.
Collapse
Affiliation(s)
- Tai-Wen Lin
- Molecular and Cell Biology, International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Chi-Chih Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- Doctoral Degree Program in Marine Biotechnology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung, 80424, Taiwan
| | - Shu-Mei Wu
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Yu-Ching Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Yi-Chuan Li
- Molecular and Cell Biology, International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
| | - Yu-Wang Su
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
| | - Chwan-Deng Hsiao
- Molecular and Cell Biology, International Graduate Program, Academia Sinica and Graduate Institute of Life Science, National Defense Medical Center, Taipei, Taiwan
- Institute of Molecular Biology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
- Doctoral Degree Program in Marine Biotechnology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei, 11529, Taiwan
| | - Hsin-Yang Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung, 80424, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung, 80424, Taiwan
| |
Collapse
|
32
|
Becker T, Song J, Pfanner N. Versatility of Preprotein Transfer from the Cytosol to Mitochondria. Trends Cell Biol 2019; 29:534-548. [PMID: 31030976 DOI: 10.1016/j.tcb.2019.03.007] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 03/27/2019] [Accepted: 03/28/2019] [Indexed: 11/16/2022]
Abstract
Mitochondrial biogenesis requires the import of a large number of precursor proteins from the cytosol. Although specific membrane-bound preprotein translocases have been characterized in detail, it was assumed that protein transfer from the cytosol to mitochondria mainly involved unselective binding to molecular chaperones. Recent findings suggest an unexpected versatility of protein transfer to mitochondria. Cytosolic factors have been identified that bind to selected subsets of preproteins and guide them to mitochondrial receptors in a post-translational manner. Cotranslational import processes are emerging. Mechanisms for crosstalk between protein targeting to mitochondria and other cell organelles, in particular the endoplasmic reticulum (ER) and peroxisomes, have been uncovered. We discuss how a network of cytosolic machineries and targeting pathways promote and regulate preprotein transfer into mitochondria.
Collapse
Affiliation(s)
- Thomas Becker
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Centre for Integrative Biological Signaling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany.
| | - Jiyao Song
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Nikolaus Pfanner
- Institute of Biochemistry and Molecular Biology, Centre for Biochemistry and Molecular Cell Research (ZBMZ), Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Centre for Integrative Biological Signaling Studies (CIBSS), University of Freiburg, 79104 Freiburg, Germany.
| |
Collapse
|
33
|
Costello JL, Passmore JB, Islinger M, Schrader M. Multi-localized Proteins: The Peroxisome-Mitochondria Connection. Subcell Biochem 2019; 89:383-415. [PMID: 30378033 DOI: 10.1007/978-981-13-2233-4_17] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Peroxisomes and mitochondria are dynamic, multifunctional organelles that play pivotal cooperative roles in the metabolism of cellular lipids and reactive oxygen species. Their functional interplay, the "peroxisome-mitochondria connection", also includes cooperation in anti-viral signalling and defence, as well as coordinated biogenesis by sharing key division proteins. In this review, we focus on multi-localised proteins which are shared by peroxisomes and mitochondria in mammals. We first outline the targeting and sharing of matrix proteins which are involved in metabolic cooperation. Next, we discuss shared components of peroxisomal and mitochondrial dynamics and division, and we present novel insights into the dual targeting of tail-anchored membrane proteins. Finally, we provide an overview of what is currently known about the role of shared membrane proteins in disease. What emerges is that sharing of proteins between these two organelles plays a key role in their cooperative functions which, based on new findings, may be more extensive than originally envisaged. Gaining a better insight into organelle interplay and the targeting of shared proteins is pivotal to understanding how organelle cooperation contributes to human health and disease.
Collapse
Affiliation(s)
| | | | - Markus Islinger
- Institute of Neuroanatomy, Center for Biomedicine & Medical Technology Mannheim, Medical Faculty Manheim, University of Heidelberg, 68167, Mannheim, Germany
| | | |
Collapse
|
34
|
Dederer V, Khmelinskii A, Huhn AG, Okreglak V, Knop M, Lemberg MK. Cooperation of mitochondrial and ER factors in quality control of tail-anchored proteins. eLife 2019; 8:45506. [PMID: 31172943 PMCID: PMC6586462 DOI: 10.7554/elife.45506] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/06/2019] [Indexed: 01/04/2023] Open
Abstract
Tail-anchored (TA) proteins insert post-translationally into the endoplasmic reticulum (ER), the outer mitochondrial membrane (OMM) and peroxisomes. Whereas the GET pathway controls ER-targeting, no dedicated factors are known for OMM insertion, posing the question of how accuracy is achieved. The mitochondrial AAA-ATPase Msp1 removes mislocalized TA proteins from the OMM, but it is unclear, how Msp1 clients are targeted for degradation. Here we screened for factors involved in degradation of TA proteins mislocalized to mitochondria. We show that the ER-associated degradation (ERAD) E3 ubiquitin ligase Doa10 controls cytoplasmic level of Msp1 clients. Furthermore, we identified the uncharacterized OMM protein Fmp32 and the ectopically expressed subunit of the ER-mitochondria encounter structure (ERMES) complex Gem1 as native clients for Msp1 and Doa10. We propose that productive localization of TA proteins to the OMM is ensured by complex assembly, while orphan subunits are extracted by Msp1 and eventually degraded by Doa10.
Collapse
Affiliation(s)
- Verena Dederer
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Anton Khmelinskii
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,Institute of Molecular Biology (IMB), Mainz, Germany
| | - Anna Gesine Huhn
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| | - Voytek Okreglak
- Calico Life Sciences LLC, South San Francisco, United States
| | - Michael Knop
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany.,Cell Morphogenesis and Signal Transduction, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Marius K Lemberg
- Centre for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg, Germany
| |
Collapse
|
35
|
Teresinski HJ, Gidda SK, Nguyen TND, Howard NJM, Porter BK, Grimberg N, Smith MD, Andrews DW, Dyer JM, Mullen RT. An RK/ST C-Terminal Motif is Required for Targeting of OEP7.2 and a Subset of Other Arabidopsis Tail-Anchored Proteins to the Plastid Outer Envelope Membrane. PLANT & CELL PHYSIOLOGY 2019; 60:516-537. [PMID: 30521026 DOI: 10.1093/pcp/pcy234] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 12/03/2018] [Indexed: 06/09/2023]
Abstract
Tail-anchored (TA) proteins are a unique class of integral membrane proteins that possess a single C-terminal transmembrane domain and target post-translationally to the specific organelles at which they function. While significant advances have been made in recent years in elucidating the mechanisms and molecular targeting signals involved in the proper sorting of TA proteins, particularly to the endoplasmic reticulum and mitochondria, relatively little is known about the targeting of TA proteins to the plastid outer envelope. Here we show that several known or predicted plastid TA outer envelope proteins (OEPs) in Arabidopsis possess a C-terminal RK/ST sequence motif that serves as a conserved element of their plastid targeting signal. Evidence for this conclusion comes primarily from experiments with OEP7.2, which is a member of the Arabidopsis 7 kDa OEP family. We confirmed that OEP7.2 is localized to the plastid outer envelope and possesses a TA topology, and its C-terminal sequence (CTS), which includes the RK/ST motif, is essential for proper targeting to plastids. The CTS of OEP7.2 is functionally interchangeable with the CTSs of other TA OEPs that possess similar RK/ST motifs, but not with those that lack the motif. Further, a bioinformatics search based on a consensus sequence led to the identification of several new OEP TA proteins. Collectively, this study provides new insight into the mechanisms of TA protein sorting in plant cells, defines a new targeting signal element for a subset of TA OEPs and expands the number and repertoire of TA proteins at the plastid outer envelope.
Collapse
Affiliation(s)
- Howard J Teresinski
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Satinder K Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Thuy N D Nguyen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Naomi J Marty Howard
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Brittany K Porter
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Nicholas Grimberg
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - Matthew D Smith
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario, Canada
| | - David W Andrews
- Sunnybrook Research Institute and Departments of Biochemistry and Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - John M Dyer
- United States Department of Agriculture, Agricultural Research Service, US Arid-Land Agricultural Research Center, Maricopa, USA
| | - Robert T Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| |
Collapse
|
36
|
Rada P, Makki A, Žárský V, Tachezy J. Targeting of tail-anchored proteins to Trichomonas vaginalis hydrogenosomes. Mol Microbiol 2019; 111:588-603. [PMID: 30506591 DOI: 10.1111/mmi.14175] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/25/2018] [Indexed: 01/17/2023]
Abstract
Tail-anchored (TA) proteins are membrane proteins that are found in all domains of life. They consist of an N-terminal domain that performs various functions and a single transmembrane domain (TMD) near the C-terminus. In eukaryotes, TA proteins are targeted to the membranes of mitochondria, the endoplasmic reticulum (ER), peroxisomes and in plants, chloroplasts. The targeting of these proteins to their specific destinations correlates with the properties of the C-terminal domain, mainly the TMD hydrophobicity and the net charge of the flanking regions. Trichomonas vaginalis is a human parasite that has adapted to oxygen-poor environment. This adaptation is reflected by the presence of highly modified mitochondria (hydrogenosomes) and the absence of peroxisomes. The proteome of hydrogenosomes is considerably reduced; however, our bioinformatic analysis predicted 120 putative hydrogenosomal TA proteins. Seven proteins were selected to prove their localization. The elimination of the net positive charge in the C-tail of the hydrogenosomal TA4 protein resulted in its dual localization to hydrogenosomes and the ER, causing changes in ER morphology. Domain mutation and swap experiments with hydrogenosomal (TA4) and ER (TAPDI) proteins indicated that the general principles for specific targeting are conserved across eukaryotic lineages, including T. vaginalis; however, there are also significant lineage-specific differences.
Collapse
Affiliation(s)
- Petr Rada
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, Vestec, 25242, Czech Republic
| | - Abhijith Makki
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, Vestec, 25242, Czech Republic
| | - Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, Vestec, 25242, Czech Republic
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University, BIOCEV, Průmyslová 595, Vestec, 25242, Czech Republic
| |
Collapse
|
37
|
Kudze T, Mendez-Dorantes C, Jalloh CS, McClellan AJ. Evidence for interaction between Hsp90 and the ER membrane complex. Cell Stress Chaperones 2018; 23:1101-1115. [PMID: 29808299 PMCID: PMC6111080 DOI: 10.1007/s12192-018-0908-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 04/24/2018] [Accepted: 05/27/2018] [Indexed: 01/04/2023] Open
Abstract
Numerous putative heat shock protein 90 (Hsp90)-interacting proteins, which could represent novel folding clients or co-chaperones, have been identified in recent years. Two separate high-throughput screens in yeast uncovered genetic effects between Hsp90 and components of the ER membrane complex (EMC), which is required for tolerance to unfolded protein response stress in yeast. Herein, we provide the first experimental evidence supporting that there is a genuine interaction of Hsp90 with the EMC. We demonstrate genetic interactions between EMC2 and the known Hsp90 co-chaperone encoded by STI1, as well as Hsp90 point mutant allele-specific differences in inherent growth and Hsp90 inhibitor tolerance in the absence and presence of EMC2. In co-precipitation experiments, Hsp90 interacts with Emc2p, whether or not Emc2p contains amino acid sequences designated as a tetratricopeptide repeat motif. Yeast with multiple EMC gene deletions exhibit increased sensitivity to Hsp90 inhibitor as well as defective folding of the well-established Hsp90 folding client, the glucocorticoid receptor. Altogether, our evidence of physical, genetic, and functional interaction of Hsp90 with the EMC, as well as bioinformatic analysis of shared interactors, supports that there is a legitimate interaction between them in vivo.
Collapse
Affiliation(s)
- Tambudzai Kudze
- Division of Science and Mathematics, Bennington College, Bennington, VT, USA
| | | | | | - Amie J McClellan
- Division of Science and Mathematics, Bennington College, Bennington, VT, USA.
| |
Collapse
|
38
|
Mateja A, Keenan RJ. A structural perspective on tail-anchored protein biogenesis by the GET pathway. Curr Opin Struct Biol 2018; 51:195-202. [PMID: 30173121 DOI: 10.1016/j.sbi.2018.07.009] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/16/2022]
Abstract
Many tail-anchored (TA) membrane proteins are targeted to and inserted into the endoplasmic reticulum (ER) by the `guided entry of tail-anchored proteins' (GET) pathway. This post-translational pathway uses transmembrane-domain selective cytosolic chaperones for targeting, and a dedicated membrane protein complex for insertion. The past decade has seen rapid progress towards defining the molecular basis of TA protein biogenesis by the GET pathway. Here we review the mechanisms underlying each step of the pathway, emphasizing recent structural work and highlighting key questions that await future studies.
Collapse
Affiliation(s)
- Agnieszka Mateja
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA
| | - Robert J Keenan
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA.
| |
Collapse
|
39
|
Cichocki BA, Krumpe K, Vitali DG, Rapaport D. Pex19 is involved in importing dually targeted tail-anchored proteins to both mitochondria and peroxisomes. Traffic 2018; 19:770-785. [DOI: 10.1111/tra.12604] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Revised: 07/17/2018] [Accepted: 07/19/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Bogdan A. Cichocki
- Interfaculty Institute of Biochemistry; University of Tübingen; Tübingen Germany
| | - Katrin Krumpe
- Interfaculty Institute of Biochemistry; University of Tübingen; Tübingen Germany
| | - Daniela G. Vitali
- Interfaculty Institute of Biochemistry; University of Tübingen; Tübingen Germany
| | - Doron Rapaport
- Interfaculty Institute of Biochemistry; University of Tübingen; Tübingen Germany
| |
Collapse
|
40
|
Manu M, Ghosh D, Chaudhari BP, Ramasamy S. Analysis of tail-anchored protein translocation pathway in plants. Biochem Biophys Rep 2018; 14:161-167. [PMID: 29872748 PMCID: PMC5986991 DOI: 10.1016/j.bbrep.2018.05.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Tail-anchored (TA) proteins are a special class of membrane proteins that carry out vital functions in all living cells. Targeting mechanisms of TA proteins are investigated as the best example for post-translational protein targeting in yeast. Of the several mechanisms, Guided Entry of Tail-anchored protein (GET) pathway plays a major role in TA protein targeting. Many in silico and in vivo analyses are geared to identify TA proteins and their targeting mechanisms in different systems including Arabidopsis thaliana. Yet, crop plants that grow in specific and/or different conditions are not investigated for the presence of TA proteins and GET pathway. This study majorly investigates GET pathway in two crop plants, Oryza sativa subsp. Indica and Solanum tuberosum, through detailed in silico analysis. 508 and 912 TA proteins are identified in Oryza sativa subsp. Indica and Solanum tuberosum respectively and their localization with respect to endoplasmic reticulum (ER), mitochondria, and chloroplast has been delineated. Similarly, the associated GET proteins are identified (Get1, Get3 and Get4) and their structural inferences are elucidated using homology modelling. Get3 models are based on yeast Get3. The cytoplasmic Get3 from O. sativa is identified to be very similar to yeast Get3 with conserved P-loop and TA binding groove. Three cytoplasmic Get3s are identified for S. tuberosum. Taken together, this is the first study to identify TA proteins and GET components in Oryza sativa subsp. Indica and Solanum tuberosum, forming the basis for any further experimental characterization of TA targeting and GET pathway mechanisms in crop plants.
Collapse
Affiliation(s)
- M.S. Manu
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune 411008, India
| | - Deepanjan Ghosh
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune 411008, India
| | - Bhushan P. Chaudhari
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune 411008, India
| | - Sureshkumar Ramasamy
- Biochemical Sciences Division, CSIR-National Chemical Laboratory, Pune 411008 India
- Academy of Scientific and Innovative Research (AcSIR), CSIR-National Chemical Laboratory, Pune 411008, India
| |
Collapse
|
41
|
Abstract
Proper localization of membrane proteins is essential for the function of biological membranes and for the establishment of organelle identity within a cell. Molecular machineries that mediate membrane protein biogenesis need to not only achieve a high degree of efficiency and accuracy, but also prevent off-pathway aggregation events that can be detrimental to cells. The posttranslational targeting of tail-anchored proteins (TAs) provides tractable model systems to probe these fundamental issues. Recent advances in understanding TA-targeting pathways reveal sophisticated molecular machineries that drive and regulate these processes. These findings also suggest how an interconnected network of targeting factors, cochaperones, and quality control machineries together ensures robust membrane protein biogenesis.
Collapse
Affiliation(s)
- Un Seng Chio
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125; , ,
| | - Hyunju Cho
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125; , ,
| | - Shu-Ou Shan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125; , ,
| |
Collapse
|
42
|
Wohlever ML, Mateja A, McGilvray PT, Day KJ, Keenan RJ. Msp1 Is a Membrane Protein Dislocase for Tail-Anchored Proteins. Mol Cell 2017; 67:194-202.e6. [PMID: 28712723 DOI: 10.1016/j.molcel.2017.06.019] [Citation(s) in RCA: 73] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/09/2017] [Accepted: 06/16/2017] [Indexed: 11/18/2022]
Abstract
Mislocalized tail-anchored (TA) proteins of the outer mitochondrial membrane are cleared by a newly identified quality control pathway involving the conserved eukaryotic protein Msp1 (ATAD1 in humans). Msp1 is a transmembrane AAA-ATPase, but its role in TA protein clearance is not known. Here, using purified components reconstituted into proteoliposomes, we show that Msp1 is both necessary and sufficient to drive the ATP-dependent extraction of TA proteins from the membrane. A crystal structure of the Msp1 cytosolic region modeled into a ring hexamer suggests that active Msp1 contains a conserved membrane-facing surface adjacent to a central pore. Structure-guided mutagenesis of the pore residues shows that they are critical for TA protein extraction in vitro and for functional complementation of an msp1 deletion in yeast. Together, these data provide a molecular framework for Msp1-dependent extraction of mislocalized TA proteins from the outer mitochondrial membrane.
Collapse
Affiliation(s)
- Matthew L Wohlever
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA
| | - Agnieszka Mateja
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA
| | - Philip T McGilvray
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA
| | - Kasey J Day
- Department of Molecular Genetics and Cell Biology, The University of Chicago, 920 East 58th Street, Chicago, IL 60637, USA
| | - Robert J Keenan
- Department of Biochemistry and Molecular Biology, The University of Chicago, 929 East 57th Street, Chicago, IL 60637, USA.
| |
Collapse
|
43
|
Costello JL, Castro IG, Camões F, Schrader TA, McNeall D, Yang J, Giannopoulou EA, Gomes S, Pogenberg V, Bonekamp NA, Ribeiro D, Wilmanns M, Jedd G, Islinger M, Schrader M. Predicting the targeting of tail-anchored proteins to subcellular compartments in mammalian cells. J Cell Sci 2017; 130:1675-1687. [PMID: 28325759 PMCID: PMC5450235 DOI: 10.1242/jcs.200204] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/14/2017] [Indexed: 12/22/2022] Open
Abstract
Tail-anchored (TA) proteins contain a single transmembrane domain (TMD) at the C-terminus that anchors them to the membranes of organelles where they mediate critical cellular processes. Accordingly, mutations in genes encoding TA proteins have been identified in a number of severe inherited disorders. Despite the importance of correctly targeting a TA protein to its appropriate membrane, the mechanisms and signals involved are not fully understood. In this study, we identify additional peroxisomal TA proteins, discover more proteins that are present on multiple organelles, and reveal that a combination of TMD hydrophobicity and tail charge determines targeting to distinct organelle locations in mammals. Specifically, an increase in tail charge can override a hydrophobic TMD signal and re-direct a protein from the ER to peroxisomes or mitochondria and vice versa. We show that subtle changes in those parameters can shift TA proteins between organelles, explaining why peroxisomes and mitochondria have many of the same TA proteins. This enabled us to associate characteristic physicochemical parameters in TA proteins with particular organelle groups. Using this classification allowed successful prediction of the location of uncharacterized TA proteins for the first time.
Collapse
Affiliation(s)
| | - Inês G Castro
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
| | - Fátima Camões
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | | | | | - Jing Yang
- Temasek Life Sciences Laboratory, Department of Biological Sciences, National University of Singapore, Singapore
| | | | - Sílvia Gomes
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | | | - Nina A Bonekamp
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | - Daniela Ribeiro
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| | | | - Gregory Jedd
- Temasek Life Sciences Laboratory, Department of Biological Sciences, National University of Singapore, Singapore
| | - Markus Islinger
- Institute of Neuroanatomy, Center for Biomedicine and Medical Technology Mannheim, University of Heidelberg, Mannheim 68167, Germany
| | - Michael Schrader
- Biosciences, University of Exeter, Exeter EX4 4QD, UK
- Centre for Cell Biology/Institute of Biomedicine & Department of Biology, University of Aveiro, Aveiro 3810-193, Portugal
| |
Collapse
|
44
|
Maestre-Reyna M, Wu SM, Chang YC, Chen CC, Maestre-Reyna A, Wang AHJ, Chang HY. In search of tail-anchored protein machinery in plants: reevaluating the role of arsenite transporters. Sci Rep 2017; 7:46022. [PMID: 28382961 PMCID: PMC5382584 DOI: 10.1038/srep46022] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 03/07/2017] [Indexed: 11/09/2022] Open
Abstract
Although the mechanisms underlying selective targeting of tail-anchored (TA) membrane proteins are well established in mammalian and yeast cells, little is known about their role in mediating intracellular membrane trafficking in plant cells. However, a recent study suggested that, in green algae, arsenite transporters located in the cytosol (ArsA1 and ArsA2) control the insertion of TA proteins into the membrane-bound organelles. In the present work, we overproduced and purified these hydrophilic proteins to near homogeneity. The analysis of their catalytic properties clearly demonstrates that C. reinhardtii ArsA proteins exhibit oxyanion-independent ATPase activity, as neither arsenite nor antimonite showed strong effects. Co-expression of ArsA proteins with TA-transmembrane regions showed not only that the former interact with the latter, but that ArsA1 does not share the same ligand specificity as ArsA2. Together with a structural model and molecular dynamics simulations, we propose that C. reinhadtii ArsA proteins are not arsenite transporters, but a TA-protein targeting factor. Further, we propose that ArsA targeting specificity is achieved at the ligand level, with ArsA1 mainly carrying TA-proteins to the chloroplast, while ArsA2 to the endoplasmic reticulum.
Collapse
Affiliation(s)
| | - Shu-Mei Wu
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Yu-Ching Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Chi-Chih Chen
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung 80424, Taiwan
- Doctoral Degree Program in Marine Biotechnology, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 11529, Taiwan
| | - Alvaro Maestre-Reyna
- Escuela Tecnica Superior de Ingenierios Industriales, Universidad Politecnica de Valencia, Valencia, Spain
| | - Andrew H.-J. Wang
- Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan
- Core Facilities for Protein Structural Analysis, Academia Sinica, Taipei, Taiwan
- PhD Program for Translational Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan
| | - Hsin-Yang Chang
- Department of Marine Biotechnology and Resources, National Sun Yat-sen University, Kaohsiung, Taiwan
- Doctoral Degree Program in Marine Biotechnology, National Sun Yat-Sen University, 70 Lien-Hai Road, Kaohsiung 80424, Taiwan
- The Asia-Pacific Ocean Research Center, National Sun Yat-sen University, Kaohsiung 804, Taiwan
| |
Collapse
|
45
|
Xing S, Mehlhorn DG, Wallmeroth N, Asseck LY, Kar R, Voss A, Denninger P, Schmidt VAF, Schwarzländer M, Stierhof YD, Grossmann G, Grefen C. Loss of GET pathway orthologs in Arabidopsis thaliana causes root hair growth defects and affects SNARE abundance. Proc Natl Acad Sci U S A 2017; 114:E1544-E1553. [PMID: 28096354 PMCID: PMC5338382 DOI: 10.1073/pnas.1619525114] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins are key players in cellular trafficking and coordinate vital cellular processes, such as cytokinesis, pathogen defense, and ion transport regulation. With few exceptions, SNAREs are tail-anchored (TA) proteins, bearing a C-terminal hydrophobic domain that is essential for their membrane integration. Recently, the Guided Entry of Tail-anchored proteins (GET) pathway was described in mammalian and yeast cells that serve as a blueprint of TA protein insertion [Schuldiner M, et al. (2008) Cell 134(4):634-645; Stefanovic S, Hegde RS (2007) Cell 128(6):1147-1159]. This pathway consists of six proteins, with the cytosolic ATPase GET3 chaperoning the newly synthesized TA protein posttranslationally from the ribosome to the endoplasmic reticulum (ER) membrane. Structural and biochemical insights confirmed the potential of pathway components to facilitate membrane insertion, but the physiological significance in multicellular organisms remains to be resolved. Our phylogenetic analysis of 37 GET3 orthologs from 18 different species revealed the presence of two different GET3 clades. We identified and analyzed GET pathway components in Arabidopsis thaliana and found reduced root hair elongation in Atget lines, possibly as a result of reduced SNARE biogenesis. Overexpression of AtGET3a in a receptor knockout (KO) results in severe growth defects, suggesting presence of alternative insertion pathways while highlighting an intricate involvement for the GET pathway in cellular homeostasis of plants.
Collapse
Affiliation(s)
- Shuping Xing
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany
| | - Dietmar Gerald Mehlhorn
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany
| | - Niklas Wallmeroth
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany
| | - Lisa Yasmin Asseck
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany
| | - Ritwika Kar
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany
| | - Alessa Voss
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany
| | - Philipp Denninger
- Centre for Organismal Studies, CellNetworks Excellence Cluster, University of Heidelberg, 69120 Heidelberg, Germany
| | - Vanessa Aphaia Fiona Schmidt
- Centre for Organismal Studies, CellNetworks Excellence Cluster, University of Heidelberg, 69120 Heidelberg, Germany
| | - Markus Schwarzländer
- Institute of Crop Science and Resource Conservation, University of Bonn, 53113 Bonn, Germany
| | - York-Dieter Stierhof
- Centre for Plant Molecular Biology, Microscopy, University of Tübingen, 72076 Tuebingen, Germany
| | - Guido Grossmann
- Centre for Organismal Studies, CellNetworks Excellence Cluster, University of Heidelberg, 69120 Heidelberg, Germany
| | - Christopher Grefen
- Centre for Plant Molecular Biology, Developmental Genetics, University of Tübingen, 72076 Tuebingen, Germany;
| |
Collapse
|
46
|
Padgett LR, Arrizabalaga G, Sullivan WJ. Targeting of tail-anchored membrane proteins to subcellular organelles in Toxoplasma gondii. Traffic 2017; 18:149-158. [PMID: 27991712 DOI: 10.1111/tra.12464] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 12/12/2016] [Accepted: 12/12/2016] [Indexed: 12/20/2022]
Abstract
Proper protein localization is essential for critical cellular processes, including vesicle-mediated transport and protein translocation. Tail-anchored (TA) proteins are integrated into organellar membranes via the C-terminus, orienting the N-terminus towards the cytosol. Localization of TA proteins occurs posttranslationally and is governed by the C-terminus, which contains the integral transmembrane domain (TMD) and targeting sequence. Targeting of TA proteins is dependent on the hydrophobicity of the TMD as well as the length and composition of flanking amino acid sequences. We previously identified an unusual homologue of elongator protein, Elp3, in the apicomplexan parasite Toxoplasma gondii as a TA protein targeting the outer mitochondrial membrane. We sought to gain further insight into TA proteins and their targeting mechanisms using this early-branching eukaryote as a model. Our bioinformatics analysis uncovered 59 predicted TA proteins in Toxoplasma, 9 of which were selected for follow-up analyses based on representative features. We identified novel TA proteins that traffic to specific organelles in Toxoplasma, including the parasite endoplasmic reticulum, mitochondrion, and Golgi apparatus. Domain swap experiments elucidated that targeting of TA proteins to these specific organelles was strongly influenced by the TMD sequence, including charge of the flanking C-terminal sequence.
Collapse
Affiliation(s)
- Leah R Padgett
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana
| | - Gustavo Arrizabalaga
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| | - William J Sullivan
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis, Indiana.,Department of Microbiology and Immunology, Indiana University School of Medicine, Indianapolis, Indiana
| |
Collapse
|
47
|
Reider Apel A, d'Espaux L, Wehrs M, Sachs D, Li RA, Tong GJ, Garber M, Nnadi O, Zhuang W, Hillson NJ, Keasling JD, Mukhopadhyay A. A Cas9-based toolkit to program gene expression in Saccharomyces cerevisiae. Nucleic Acids Res 2017; 45:496-508. [PMID: 27899650 PMCID: PMC5224472 DOI: 10.1093/nar/gkw1023] [Citation(s) in RCA: 168] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Revised: 10/12/2016] [Accepted: 10/18/2016] [Indexed: 01/08/2023] Open
Abstract
Despite the extensive use of Saccharomyces cerevisiae as a platform for synthetic biology, strain engineering remains slow and laborious. Here, we employ CRISPR/Cas9 technology to build a cloning-free toolkit that addresses commonly encountered obstacles in metabolic engineering, including chromosomal integration locus and promoter selection, as well as protein localization and solubility. The toolkit includes 23 Cas9-sgRNA plasmids, 37 promoters of various strengths and temporal expression profiles, and 10 protein-localization, degradation and solubility tags. We facilitated the use of these parts via a web-based tool, that automates the generation of DNA fragments for integration. Our system builds upon existing gene editing methods in the thoroughness with which the parts are standardized and characterized, the types and number of parts available and the ease with which our methodology can be used to perform genetic edits in yeast. We demonstrated the applicability of this toolkit by optimizing the expression of a challenging but industrially important enzyme, taxadiene synthase (TXS). This approach enabled us to diagnose an issue with TXS solubility, the resolution of which yielded a 25-fold improvement in taxadiene production.
Collapse
Affiliation(s)
- Amanda Reider Apel
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - Leo d'Espaux
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - Maren Wehrs
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - Daniel Sachs
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - Rachel A Li
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Department of Plant and Microbial Biology, University of California, Berkeley, California, CA 94720, USA
| | - Gary J Tong
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - Megan Garber
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - Oge Nnadi
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| | - William Zhuang
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, CA 94720, USA
| | - Nathan J Hillson
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
- DOE Joint Genome Institute, Walnut Creek, California, CA 94598, USA
| | - Jay D Keasling
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
- Department of Chemical and Biomolecular Engineering, University of California, Berkeley, California, CA 94720, USA
- DOE Joint Genome Institute, Walnut Creek, California, CA 94598, USA
- The Novo Nordisk Foundation Center for Sustainability, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Aindrila Mukhopadhyay
- DOE Joint BioEnergy Institute, Emeryville, California, CA 94608, USA
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, California, CA 94720, USA
| |
Collapse
|
48
|
Evidence for Amino Acid Snorkeling from a High-Resolution, In Vivo Analysis of Fis1 Tail-Anchor Insertion at the Mitochondrial Outer Membrane. Genetics 2016; 205:691-705. [PMID: 28007883 PMCID: PMC5289845 DOI: 10.1534/genetics.116.196428] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Accepted: 12/12/2016] [Indexed: 01/03/2023] Open
Abstract
Proteins localized to mitochondria by a carboxyl-terminal tail anchor (TA) play roles in apoptosis, mitochondrial dynamics, and mitochondrial protein import. To reveal characteristics of TAs that may be important for mitochondrial targeting, we focused our attention upon the TA of the Saccharomyces cerevisiaeFis1 protein. Specifically, we generated a library of Fis1p TA variants fused to the Gal4 transcription factor, then, using next-generation sequencing, revealed which Fis1p TA mutations inhibited membrane insertion and allowed Gal4p activity in the nucleus. Prompted by our global analysis, we subsequently analyzed the ability of individual Fis1p TA mutants to localize to mitochondria. Our findings suggest that the membrane-associated domain of the Fis1p TA may be bipartite in nature, and we encountered evidence that the positively charged patch at the carboxyl terminus of Fis1p is required for both membrane insertion and organelle specificity. Furthermore, lengthening or shortening of the Fis1p TA by up to three amino acids did not inhibit mitochondrial targeting, arguing against a model in which TA length directs insertion of TAs to distinct organelles. Most importantly, positively charged residues were more acceptable at several positions within the membrane-associated domain of the Fis1p TA than negatively charged residues. These findings, emerging from the first high-resolution analysis of an organelle targeting sequence by deep mutational scanning, provide strong, in vivo evidence that lysine and arginine can “snorkel,” or become stably incorporated within a lipid bilayer by placing terminal charges of their side chains at the membrane interface.
Collapse
|
49
|
Rao M, Okreglak V, Chio US, Cho H, Walter P, Shan SO. Multiple selection filters ensure accurate tail-anchored membrane protein targeting. eLife 2016; 5. [PMID: 27925580 PMCID: PMC5214336 DOI: 10.7554/elife.21301] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 12/06/2016] [Indexed: 11/13/2022] Open
Abstract
Accurate protein localization is crucial to generate and maintain organization in all cells. Achieving accuracy is challenging, as the molecular signals that dictate a protein's cellular destination are often promiscuous. A salient example is the targeting of an essential class of tail-anchored (TA) proteins, whose sole defining feature is a transmembrane domain near their C-terminus. Here we show that the Guided Entry of Tail-anchored protein (GET) pathway selects TA proteins destined to the endoplasmic reticulum (ER) utilizing distinct molecular steps, including differential binding by the co-chaperone Sgt2 and kinetic proofreading after ATP hydrolysis by the targeting factor Get3. Further, the different steps select for distinct physicochemical features of the TA substrate. The use of multiple selection filters may be general to protein biogenesis pathways that must distinguish correct and incorrect substrates based on minor differences.
Collapse
Affiliation(s)
- Meera Rao
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Voytek Okreglak
- Howard Hughes Medical Institute, University of California, San Francisco, United States.,Department of Biochemistry and Biophysics, University of California, San Francisco, United States
| | - Un Seng Chio
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Hyunju Cho
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| | - Peter Walter
- Howard Hughes Medical Institute, University of California, San Francisco, United States.,Department of Biochemistry and Biophysics, University of California, San Francisco, United States
| | - Shu-Ou Shan
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, United States
| |
Collapse
|
50
|
Shigemitsu S, Cao W, Terada T, Shimizu K. Development of a prediction system for tail-anchored proteins. BMC Bioinformatics 2016; 17:378. [PMID: 27634135 PMCID: PMC5025589 DOI: 10.1186/s12859-016-1202-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 08/24/2016] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND "Tail-anchored (TA) proteins" is a collective term for transmembrane proteins with a C-terminal transmembrane domain (TMD) and without an N-terminal signal sequence. TA proteins account for approximately 3-5 % of all transmembrane proteins that mediate membrane fusion, regulation of apoptosis, and vesicular transport. The combined use of TMD and signal sequence prediction tools is typically required to predict TA proteins. RESULTS Here we developed a prediction system named TAPPM that predicted TA proteins solely from target amino acid sequences according to the knowledge of the sequence features of TMDs and the peripheral regions of TA proteins. Manually curated TA proteins were collected from published literature. We constructed hidden markov models of TA proteins as well as three different types of transmembrane proteins with similar structures and compared their likelihoods as TA proteins. CONCLUSIONS Using the HMM models, we achieved high prediction accuracy; area under the receiver operator curve values reaching 0.963. A command line tool written in Python is available at https://github.com/davecao/tappm_cli .
Collapse
Affiliation(s)
- Shunsuke Shigemitsu
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
| | - Wei Cao
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
| | - Tohru Terada
- Agricultural Bioinformatics Research Unit, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
| | - Kentaro Shimizu
- Department of Biotechnology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657 Japan
| |
Collapse
|